VIDEO DEMO - https://youtube.com/shorts/WacbBrRpxEw?feature=share

Framing the Problem

Splitting expenses with friends is currently a chore that creates social friction and awkward conversations. People often forget to repay friends, delay payments, or feel uncomfortable sending reminders, which can lead to damaged relationships and financial stress.

SplitStar transforms expense splitting from a tedious obligation into an engaging and rewarding experience. By combining:

• Stevie the Star, our lovable mascot, who reacts to your payment behaviour

• Gamification through points and achievement systems

• Real rewards (vouchers, stocks, cashback) for paying friends back on time

• Social accountability through friend group leaderboards and shareable milestones

We make financial responsibility feel fun, reduce social friction around money, and build better financial habits among young adults.

Idea Explanation

SplitStar is a mobile-first expense splitting app that gamifies financial responsibility through a rewards-based system centred around Stevie the Star, our mischievous character.

How it fixes the problem:

• Eliminates awkwardness: Stevie sends playful reminders instead of you having to nag friends directly

  • Examples of Reminders:

    • "You brokie give your friend money?!"

    • "Is your bank account sick?"

    • "You're not Tate McRae, stop being Greedy!"

    • "Can you pay your bills?! I don't think you do!"

    • "This is giving broke, pay your friend!"

    • "You ate and didn't pay the bill!"

    • "YASSS BROKE BADDIEEEE!"

    • "I'm losing my shine, pay your friends back!"

    • "Stop being goofy, just pay your friends!"

• Incentivises timely payment: Users earn points for paying on time, which unlock real-world rewards (gift cards, cashback, fractional stocks)

• Creates positive reinforcement: Instead of guilt-based reminders, users are motivated by achievements, and watching Stevie celebrate their responsible behaviour

• Makes it social and fun: Leaderboards within friend groups turn financial responsibility into friendly competition

• Builds habits: The gamification mechanics create consistent engagement and develop long-term financial responsibility

Implementation

Tech Stack

Frontend:

• Next.js

• React

• TypeScript

UI/Styling:

• Tailwind CSS

• shadcn/ui components

• Radix UI primitives

Backend/Database:

• Supabase

Additional Libraries:

• React Hook Form + Zod (forms/validation)

• Lucide React (icons)

• Recharts (charts)

• date-fns (date handling)

Challenges

• Trying to come up with a unique selling point because the concept of an expense-splitting app already exists

  • We mitigated this by adding Stevie the Star to encourage people to pay their friends

  • Added a rewards system that reframes the user experience: yes, you're paying friends back (money out), but you're earning points toward discounts, vouchers, and even stocks (value in)

• Balancing gamification with financial sensitivity

  • Ensured Stevie's personality is satirical, fun and quirky

  • Made reminders customisable so users maintain control

• Designing a sustainable rewards economy

  • Calculated reward costs against potential revenue from transaction fees and premium subscriptions

  • Explored brand partnership models where companies subsidise vouchers for user acquisition

Accomplishments

• We built a functional prototype to demo what we are trying to do

• We created branding that incorporates Starling Bank's colours, but was still unique to our app

• We came up with different ways to make expense-splitting more fun with friends, to make an awkward thing like paying people back a little less awkward

• Developed a complete rewards framework that could scale from the most viable product (MVP) to a full product

• Created a unique value proposition that differentiates SplitStar in a crowded market

Next Steps

• Monthly AI Summaries - "Stevie's Wrapped": Spotify-style personalised recaps showing payment stats, streaks, and fun insights (e.g., "You paid back £437 this month - that's 12 Greggs trips!"). Shareable graphics for social media to drive viral growth.

• Stevie AI Chatbot: Transform Stevie into an interactive assistant for natural language expense management. Users can ask "Stevie, split this £60 bill 4 ways" or "Who do I owe right now?" making the app more conversational and intuitive.

• Recurring Splits: Set up automated monthly payments for rent, utilities, and subscriptions with housemates. Never forget regular expenses again.

• Group Trip Planner: Track shared expenses for weekend getaways, holidays, or events. See running totals and settle up at the end with one tap.

• Premium Tier ("Stevie Gold"): Subscription offering 2x points on all payments, exclusive custom Stevie skins and animations, priority customer support, and ad-free experience. Revenue from premiums helps fund the rewards system sustainably.